It has been found very desirable to tint sheets of writing paper, especially sheets which are formed into pads of lined paper sometimes called "legal pads". The traditional yellow color, and later a pastel green, have now yielded to a whole spectrum of pastel colors which are available in these pads of writing paper. In addition to the general consumer preference for pads of tinted writing paper and sometimes individual consumer preferences for a specific color or shade, there is evidence and certainly the perception that certain tinted colors can significantly reduce eye strain by reducing glare in certain light environments and in providing a more visually effective surface for different kinds and colors of writing ink.
The standard method for the manufacture of pads of tinted writing paper is to begin with sheets of vat-dyed paper. These sheets were dyed during the process of their manufacture in order to achieve permanent coloring and to achieve uniform coloring.
One of the significant problems with the use of vat-dyed paper as a starting point for pads of tinted writing paper is that it is extremely difficult to remove the color dye from the paper in order to recycle the paper for reuse. In fact, using present dye extraction technology, it is impossible, as a practical matter, to effectively remove the color. Among other problems with this situation, is that, if one were to attempt to recycle colored paper, in a plan which would not necessarily remove all of the dye, it would be necessary to separate and separately recycle each of the various shades of each of the various colors. Otherwise, the resulting mixed color products would have inconsistent and probably undesirable colors. As a result, it is essentially impractical to attempt to recycle vat-dyed writing paper into any uses other than those for which color is not an issue. Unfortunately, for recyclers, those kinds of uses are generally of very low value. This problem is not necessarily present in white paper and the economics of recycling white paper back through the high value writing paper cycle has much more favorable economics and practicality.
Another difficulty with the manufacture of pads of tinted writing paper is that the mills which manufacture the paper tend to manufacture the specific color and tint of the paper in specific mill runs. As a result, a specific color of paper may only be available at certain times when the mill feels it is appropriate to set up to run that color. Thus the paper processor who wishes to make pads of colored writing paper cannot rely on the timeliness of the sources of paper. The result is that the paper processor typically must purchase the colors that he wishes when they are available and stockpile them based on projections of need. Furthermore, this special scheduling and storage problem causes the cost of these tinted papers to be significantly greater than one would expect compared to the cost of white paper.
These and other difficulties experienced with the prior art products have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a tinted writing paper which can easily and inexpensively be recycled for reuse as writing paper or other high value paper product.
Another object of this invention is the provision of a tinted writing paper which is formed from standard white paper stock.
A further object of the present invention is the provision of tinted paper which can be controlled in its color by the writing pad manufacturer without reliance on the coloring activities of the paper manufacturer.
It is another object of the present invention to provide tinted paper which can incorporate into its tinting function, either certain textures of color or patterns which either display words or symbols.
A still further object of the invention is the provision of tinted paper which provides the writing pad manufacturer with maximum control over his product.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of pans set forth in the specification and covered by the claims appended hereto.